Abaixo está uma instrução que descreve uma tarefa de geração de SQL, combinada com uma entrada que fornece mais contexto sobre os esquemas de tabela disponíveis. Escreva o código SQL que responda adequadamente à solicitação
 ###Instrução: qual é a data da vaga quando a data de nomeação é 1 de janeiro de 2009?
 ###Tabelas: CREATE TABLE casts (casts_id AUTO_INCREMENT PRIMARY KEY, Role VARCHAR, Original Broadway cast VARCHAR, Closing Broadway cast VARCHAR, Original US Tour cast VARCHAR, Original NonEquity Tour cast VARCHAR, Original São Paulo cast VARCHAR, Original Lima cast VARCHAR) CREATE TABLE important_originating_express_trains (important_originating_express_trains_id AUTO_INCREMENT PRIMARY KEY, Train No. VARCHAR, Train Name VARCHAR, Destination VARCHAR, Category VARCHAR, Frequency VARCHAR) CREATE TABLE season_2_1997–98 (season_2_1997–98_id AUTO_INCREMENT PRIMARY KEY, Series # INT, Season # INT, Title VARCHAR, Directed by VARCHAR, Written by VARCHAR, Original air date VARCHAR) CREATE TABLE managerial_changes (managerial_changes_id AUTO_INCREMENT PRIMARY KEY, Team VARCHAR, Outgoing manager VARCHAR, Manner of departure VARCHAR, Date of vacancy VARCHAR, Replaced by VARCHAR, Date of appointment VARCHAR, Position in table VARCHAR) CREATE TABLE most-visited_countries_by_international_tourist_arrivals (most-visited_countries_by_international_tourist_arrivals_id AUTO_INCREMENT PRIMARY KEY, Rank INT, Country VARCHAR, UNWTO Region VARCHAR, International tourist arrivals (2012) VARCHAR, International tourist arrivals (2011) VARCHAR, Change (2011 to 2012) VARCHAR, Change (2010 to 2011) VARCHAR)  
SELECT Date of vacancy FROM managerial_changes WHERE Date of appointment = 1 january 2009